The present invention relates to a golf ball which has a high rebound, a low spin and a good feel upon impact, and is thus suitable for the ordinary amateur golfer who places greater importance on the distance and feel of the ball than its spin performance.
Recently, as the golfing population has grown, the qualities that golfers desire in a golf ball have become more diverse and individualized. Various efforts have been made to develop balls with constructions that satisfy such desires.
For example, JP-A 9-313643 (Patent Reference 1) discloses a golf ball in which providing the core with a proper hardness distribution and also providing the overall golf ball with a proper hardness distribution enables all of the following qualities to be achieved: good flight performance, good durability, good feel upon impact and good controllability.
JP-A 10-305114 (Patent Reference 2) discloses a golf ball which has a large number of dimples on the surface of the cover, and in which the hardness balance between the core, intermediate layer and cover has been optimized and the dimples have also been optimized. These characteristics provide the golf ball with a good feel on impact and a good flight performance regardless of the head speed at which it is struck.
JP-A 2001-218873 (Patent Reference 3) describes a golf ball in which the intermediate layer and/or cover are made of specific materials and the Shore D hardness of each layer is set within specific ranges, thereby causing the forces applied to the ball when it is struck to be effectively dispersed throughout the ball so that energy loss during ball deformation is reduced, enhancing both rebound and carry. This ball is also thereby conferred with both a soft feel and a good spin performance (controllability).
JP-A 2002-210042 (Patent Reference 4) describes a golf ball in which, by specifying the JIS-C hardness at the center of the core, the JIS-C hardness at the surface of the core and the core diameter, specifying the material, JIS-C hardness and thickness of the intermediate layer and specifying the material, JIS-C hardness and thickness of the cover, and by at the same time optimizing the JIS-C hardness difference between the intermediate layer and the core surface, the JIS-C hardness difference between the cover and the intermediate layer, the hardness distribution between the core, intermediate layer and cover, and the dimple arrangement, there can be obtained a very soft feel upon impact yet a good durability, reduced flight variability, a straight flight path and increased carry owing to a low spin, a high launch angle and high rebound.
However, there is room for further improvement in these golf balls from the standpoint of achieving a better rebound, a lower spin and a soft feel.
JP No. 2828924 (Patent Reference 5) discloses art for achieving a low spin upon impact and a high launch angle by providing a large hardness difference between the core and the golf ball. However, because this golf ball has a large difference in deformation between the core and the cover at the time of impact and is thus prone to a loss of energy, there is room for further improvement in terms of rebound. Moreover, this golf ball has a relatively thick cover. Therefore, when a soft cover is used, the ball undergoes a decrease in rebound and takes on excessive spin, resulting in a reduced carry. On the other hand, the use of a hard cover tends to lead to a poor feel upon impact. Hence, there is room for improvement with respect to these characteristics as well.